Did running a monitoring node become harder ?

I remember back in PoW times, that I could sync the blockchain on a Raspberry pi 8gb with 1 or 2 tb iirc (but storage is not the issue here). I used it to get access to the memory pool, relay and verify transactions without mining.

However, since the merge, it looks like the requirements have gone up, having to run both an execution and a consensus client.

How is that so (a raspi like that isn't powerful anymore, as stated on the ethonarm website), and what can is the bare minimum I can do to verify and relay the transactions on mainnet ?

It feels like it is a step backwards, as it's harder to just verify.